BVR question

[Spikeweed]

I have a stupid question. If I have a STT lock on the bandit and I shoot an amraam,  will he receive a immediate missile launch warning? Or he only has a missile warning when the amraam goes active?

Edited June 25, 2023 by Spikeweed

[Hobel]

vor 1 Stunde schrieb Spikeweed:

I have a stupid question. If I have a STT lock on the bandit and I shoot an amraam,  will he receive a immediate missile launch warning? Or he only has a missile warning when the amraam goes active?

 

only when the missle goes active and this happens when it is still 15km away from the target

[Spikeweed]

5 hours ago, Hobel said:

only when the missle goes active and this happens when it is still 15km away from the target

The target receives immediate lock warning when I get him STT, but when I shoot a missile there’s no additional missile launch warning. Is that correct? 

[darkman222]

In reality if you STT lock a hostile he will receive a STT lock from your aircraft. If you fire your Amraam it will be guided through the Link16 from your jet, thus no missile warning yet. So if you just RWS "soft locked" him he wont hear any warning. Just nails from an F16 (whis is not audible currently in the F16). If you STT lock him, he will get a F16 spike warning from his RWR. When the missile is not guided any more by your jet he will get a missile warning.

Out out curiosity I tried it once between my 2 PCs with two DCS installations. It seemed to work that way. At least one year ago. When the F16 will get the PRF tone library the audible RWR sounds will change a lot. Be aware of what your learn now you'll need to unlearn at some point.

Edited June 26, 2023 by darkman222

[Tholozor]

9 hours ago, darkman222 said:

If you fire your Amraam it will be guided through the Link16 from your jet

Link16 isn't related to missile guidance in this way. The ownship FCR has its own missile command datalink for AMRAAM guidance, otherwise F-16s wouldn't have been able to guide 120s prior to the addition of the MIDS-LVT (e.g. Desert Storm).

[skywalker22]

19 hours ago, darkman222 said:

In reality if you STT lock a hostile he will receive a STT lock from your aircraft. If you fire your Amraam it will be guided through the Link16 from your jet, thus no missile warning yet. So if you just RWS "soft locked" him he wont hear any warning. Just nails from an F16 (whis is not audible currently in the F16). If you STT lock him, he will get a F16 spike warning from his RWR. When the missile is not guided any more by your jet he will get a missile warning.

Out out curiosity I tried it once between my 2 PCs with two DCS installations. It seemed to work that way. At least one year ago. When the F16 will get the PRF tone library the audible RWR sounds will change a lot. Be aware of what your learn now you'll need to unlearn at some point.

 

There is no Link16 between AMRAAM and a mothership, you confused terms.

Before the AIM-120C missile transitions to its autonomous "pitbull" mode (better said, when it goes HPRF and then MPRF active), it relies on guidance information provided by the launching aircraft's fire control system. During the initial phase of the missile's flight, it is guided using a technique called "midcourse guidance."  Midcourse guidance involves the continuous exchange of information between the launching aircraft and the missile. The launching aircraft's radar tracks the target and provides continuous updates on its position and velocity. Using this information, the launching aircraft's fire control system calculates the optimal flight path for the missile to intercept the target.  The guidance commands are then transmitted to the AIM-120C missile either via an internal data link or through continuous radar illumination from the launching aircraft. The missile receives these commands and adjusts its flight trajectory accordingly to guide it towards the predicted intercept point.

So launch warning for the bandit will occur when AMRRAM switches from mothership guidance to it's own (when it goes into HPRF or MPRF stage).

[darkman222]

4 hours ago, skywalker22 said:

So launch warning for the bandit will occur when AMRRAM switches from mothership guidance to it's own (when it goes into HPRF or MPRF stage).

Yep. If I was unclear, that was what I was trying to say. But this leaves another off topic question. Why can the RWR detect a launched semi active missile Aim7 Sparrow which is also guided through motership illumination and some kind of data link to the target, but why cant the RWR detect the guidance of the AIM120?

[GGTharos]

On 6/25/2023 at 8:27 AM, Spikeweed said:

The target receives immediate lock warning when I get him STT, but when I shoot a missile there’s no additional missile launch warning. Is that correct? 

It shouldn't be correct.  The M-Link should be detectable by the targeted RWR.   Lock + M-Link should trigger a launch warning for the RWR.

[skywalker22]

4 hours ago, darkman222 said:

Yep. If I was unclear, that was what I was trying to say. But this leaves another off topic question. Why can the RWR detect a launched semi active missile Aim7 Sparrow which is also guided through motership illumination and some kind of data link to the target, but why cant the RWR detect the guidance of the AIM120?

The AIM-120C AMRAAM (Advanced Medium-Range Air-to-Air Missile) is designed to minimize its detectability by enemy aircraft's radar warning receiver (RWR) systems until it goes active. The AIM-120C utilizes a "fire-and-forget" capability, meaning that once it is launched, it can continue its guidance without requiring continuous illumination from the launching aircraft's radar.

[darkman222]

But the OP question points to this exact moment

1 hour ago, skywalker22 said:

The AIM-120C utilizes a "fire-and-forget" capability, meaning that once it is launched, it can continue its guidance without requiring continuous illumination from the launching aircraft's radar.

You need to guide it until it goes self guided. With STT, only spikes from the locking aircraft no missile warning. With RWS softlock only RWR nails, no misile launch warning. When the AIM120 goes pitbull: Missile warning.

With the AIM7 immidiate missile warning when being guided through the mothership.

That should be or was the case when I did some tests with the F18 with Aim120 but also with Aim7, more than one year ago.

[skywalker22]

1 hour ago, darkman222 said:

But the OP question points to this exact moment

You need to guide it until it goes self guided. With STT, only spikes from the locking aircraft no missile warning. With RWS softlock only RWR nails, no misile launch warning. When the AIM120 goes pitbull: Missile warning.

With the AIM7 immidiate missile warning when being guided through the mothership.

That should be or was the case when I did some tests with the F18 with Aim120 but also with Aim7, more than one year ago.

You are correct, and I apologize for the incorrect statement. The AIM-120C AMRAAM does require continuous illumination from the launching aircraft's radar until it transitions to its own active radar homing mode.

Edited June 27, 2023 by skywalker22

[Pavlin_33]

3 hours ago, darkman222 said:

But the OP question points to this exact moment

You need to guide it until it goes self guided. With STT, only spikes from the locking aircraft no missile warning. With RWS softlock only RWR nails, no misile launch warning. When the AIM120 goes pitbull: Missile warning.

With the AIM7 immidiate missile warning when being guided through the mothership.

That should be or was the case when I did some tests with the F18 with Aim120 but also with Aim7, more than one year ago.

Why no RWR warning when launched via STT? 120 is receiving M-Link data (before pitbull) and this combined with STT should trigger a launch warning. Same happens for R-27, for example.

Does Aim-7 have mid-course guidance?

Edited June 27, 2023 by Pavlin_33

[TheBigTatanka]

You get a launch warning from fox-1 shooters (AA-10s and Sparrows) because at launch the shooter turns on a CW antenna to illuminate target aircraft. If the target aircraft's RWR gear is programed to detect that CW illumination, you get a missile launch indication.

Is it theoretically possible that you could program a RWR gear to trigger a missile launch warning from a Fox-3 shooter by combining STT + some datalink waves out there? Maybe. How do you know where those datalink waves came from? How strong is that single if it's being directed towards a lofted missile and not the targeted jet? Does the enemy have the EW signature of those waves? Do they change?

It's very very unlikely that an RWR set (especially the very old flanker and fulcrum sets in DCS) would get any launch indication until MPRF. Don't forget how very old the Russian jets in DCS are.

Meanwhile, the fox-1 shooters are blasting the target with a CW antenna.... RWR gear is going to pick that up and give you a missile launch warning.

Also.... Don't be reliant on that RWR gear. All you should care about is: 1. Was I ever spiked? 2. Distance to the leading edge. 3. Type of shooter you face.



Sent from my Pixel 4a (5G) using Tapatalk

[MARLAN_]

16 hours ago, skywalker22 said:

There is no Link16 between AMRAAM and a mothership, you confused terms.

Before the AIM-120C missile transitions to its autonomous "pitbull" mode (better said, when it goes HPRF and then MPRF active), it relies on guidance information provided by the launching aircraft's fire control system. During the initial phase of the missile's flight, it is guided using a technique called "midcourse guidance."  Midcourse guidance involves the continuous exchange of information between the launching aircraft and the missile. The launching aircraft's radar tracks the target and provides continuous updates on its position and velocity. Using this information, the launching aircraft's fire control system calculates the optimal flight path for the missile to intercept the target.  The guidance commands are then transmitted to the AIM-120C missile either via an internal data link or through continuous radar illumination from the launching aircraft. The missile receives these commands and adjusts its flight trajectory accordingly to guide it towards the predicted intercept point.

So launch warning for the bandit will occur when AMRRAM switches from mothership guidance to it's own (when it goes into HPRF or MPRF stage).

FYI and for other readers - the AMRAAM doesn't necessarily always go from HPRF -> MPRF active, it could immediately go from inactive to MPRF active depending on the situation (closure/aspect)

I only bring it up so readers/ED don't implement the AMRAAM this way if they ever actually implement HPRF in the AMRAAM.

[Aquorys]

There is generally a lot of hilariously detailed misinformation in this thread, and I'd say we'll just leave it at that before anyone goes to jail. 

[GGTharos]

1 hour ago, TheBigTatanka said:

You get a launch warning from fox-1 shooters (AA-10s and Sparrows) because at launch the shooter turns on a CW antenna to illuminate target aircraft.

CW antennae have been a thing of the past since the 70's with very little exception.  The clue is in the signal waveform, literally.  Be it an injected guidance signal or M-Link, it is injected into the waveform and it is detectable.

It is far, far more likely that the earlier SPO-15 would be unable to detect the AMRAAM's seeker, and far more likely to detect the above situation.

Edited June 27, 2023 by GGTharos

[Hulkbust44]

6 hours ago, Pavlin_33 said:

Why no RWR warning when launched via STT? 120 is receiving M-Link data (before pitbull) and this combined with STT should trigger a launch warning. Same happens for R-27, for example.

Does Aim-7 have mid-course guidance?

 

No way in hell an RWR, even a modern NATO model from our DCS era would pick up MDL. It just doesn't make sense, with the frequency agility, low power output, and the fact that data beamed to a missile would be nowhere near the LOS of the target. 

Yes

[GGTharos]

10 hours ago, Hulkbust44 said:

No way in hell an RWR, even a modern NATO model from our DCS era would pick up MDL. It just doesn't make sense, with the frequency agility, low power output, and the fact that data beamed to a missile would be nowhere near the LOS of the target. 

Yes

You're saying an RWR couldn't pick up a signal injected into the STT waveform?  Why?  All the stuff you said is just hand-waving, and that's what makes no sense.   The radar emits the DL the same as any other signal, it 'lives' inside whatever waveform the radar is emitting.  Where you have an STT signal with nothing extra between pulses in the cycle, now you have an extra thing being added once every so often - could be between every pulse, could be every quarter of a second.  It's there, the missile detects it, what makes you believe the RWR with its larger antennae wouldn't?

[Aquorys]

One simple way to prevent the interpretation of the presence or absence of a data link is to constantly emit an encrypted data link, either sending data packets marked as guidance information with target information in the payload section, or data packets marked as dummy information with random content in the payload section. Similar problems and solutions have been studied and known for decades in a field of information technology security called covert channel analysis.

Edited June 28, 2023 by Aquorys

[Hulkbust44]

7 hours ago, GGTharos said:

The radar emits the DL the same as any other signal, it 'lives' inside whatever waveform the radar is emitting.

Where do you get that from? Makes no sense to me whatsoever. If you have an STT your're looking at a highly concentrated narrow beam, for argument's sake let's say it's 2 deg. A BVR-launched AIM-120 will loft and be nowhere near that beam until it's close to the target, where it would already be active. So it clearly doesn't work like that, and we know that (for the Hornet at least) MDL will be communicated via the sidelobes as well. 

[GGTharos]

5 hours ago, Hulkbust44 said:

Where do you get that from? Makes no sense to me whatsoever.  If you have an STT your're looking at a highly concentrated narrow beam, for argument's sake let's say it's 2 deg. A BVR-launched AIM-120 will loft and be nowhere near that beam until it's close to the target, where it would already be active. So it clearly doesn't work like that, and we know that (for the Hornet at least) MDL will be communicated via the sidelobes as well. 

The radar beam is an engineering definition of the power density based on whatever criteria.  Did you know that 'the beam' in the APG-70 is considered to be 1.5 deg at long range, but once you drop into a 20nm VSD it opens up to 3.4 degrees?  Magic, right?  That would be because 'the beam' exists everywhere.

And yes the radar has side-lobes, and the M-Link exists where they exist ... including the main-lobe, which is what would trigger the RWR - in other words, it's nothing special when it comes to the radar emission.   When you launch a sparrow, a guidance signal is injected into STT (ie. it's not 'just STT' any more) - if you launch an AMRAAM, it is likely that the MDL signal is injected in that space instead.   And while we we don't have the waveform specifications for the 120, we do have them for some other missiles and we can make an educated guess regarding what the AMRAAM does - to keep it simple, STT + some other injected signal in that waveform = missile launch.

Edited June 29, 2023 by GGTharos